Tripelennamine, sold under the brand name Pyribenzamine by

Novartis Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loc ...

, is a drug that is used as an antipruritic and first-generation

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provid ...

. It can be used in the treatment of

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...

, hay fever,

rhinitis Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip. The inflammation is caused by viruses, bacteria, irrita ...

, and

urticaria Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-last ...

, but is now less common as it has been replaced by newer antihistamines. The drug was patented at CIBA, which merged with Geigy into Ciba-Geigy, and eventually becoming Novartis.

Medical uses

Where and when it is/was in common use, tripelennamine is used much like other mildly-anticholinergic antihistamines to treat conditions of the upper respiratory tract arising from illnesses and hay fever. It can be used alone or in combination with other agents to have the desired effect. Cough medicines of the general formula tripelennamine + codeine/dihydrocodine/hydrocodone ± expectorant ± decongestant(s) are popular where available. Among these are the Pyribenzamine cough syrups which contain codeine, with and without decongestants, listed in the 1978 ''Physicians' Desk Reference''; the codeine-tripelennamine synergy is well-known and makes such mixtures more useful for their intended purposes.

Side effects

Tripelennamine is mildly sedating. Other side effects can include irritation,

dry mouth Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause. This symptom is very common and is often seen as a side eff ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

, and

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...

. A large study on people 65 years old or older linked the development of Alzheimer's disease and other forms of dementia to the "higher cumulative" use of first-generation antihistamines, due to their

anticholinergic Anticholinergics (anticholinergic agents) are substances that block the action of the neurotransmitter called acetylcholine (ACh) at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous sys ...

properties.

Pharmacology

Pharmacodynamics

Tripelennamine acts primarily as an

, or H₁ receptor antagonist. It has little to no

activity, with 180-fold selectivity for the H₁ receptor over the

muscarinic acetylcholine receptor Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-rec ...

s (for comparison,

diphenhydramine Diphenhydramine (DPH) is an antihistamine and sedative mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremor in parkinsonism, and nausea. It is taken by mouth, injected into ...

had 20-fold selectivity for the H₁ receptor). In addition to its antihistamine properties, tripelennamine also acts as a weak serotonin-norepinephrine-dopamine reuptake inhibitor (SNDRI).

Pharmacokinetics

The

elimination half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...

of tripelennamine is 4 to 6 hours. In a clinical study, the half-life of tripelennamine following intramuscular injection of 50 to 100 mg was 2.9 to 4.4 hours.

History

Tripelennamine was first synthesized in 1946 by

Carl Djerassi Carl Djerassi (October 29, 1923 – January 30, 2015) was an Austrian-born Bulgarian-American pharmaceutical chemist, novelist, playwright and co-founder of Djerassi Resident Artists Program with Diane Wood Middlebrook. He is best known for his ...

, working in the laboratory of Charles Huttrer at CIBA, shortly after Djerassi got his B.S. It was his first

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

Society and culture

Availability

Tripelennamine is no longer available in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

References

{{Monoamine reuptake inhibitors Aminopyridines CYP2D6 inhibitors H1 receptor antagonists Serotonin–norepinephrine–dopamine reuptake inhibitors